GPS image acquisition and tracking system

ABSTRACT

A method for the onboard locating and tracking of remotely located targets from a search vehicle. These functions are accomplished by first receiving two separate location signals onboard the search vehicle. The first location signal corresponds to the location of the target and is transmitted by way of a transmitter to a transceiver positioned onboard the search vehicle. The second location signal corresponds to the location of the search vehicle itself, and is received by way of a receiver located onboard the search vehicle. These first and second location signals are processed together by a control processor to determine a relative location between the target and the search vehicle. The control processor then moves an image acquisition device, which includes a camera, in accordance with the relative location, and then visually captures the target with the camera. Visual contact is then maintained by continuously repeating the above described process.

RELATED APPLICATIONS

[0001] This is a continuation of U.S. patent application Ser. No. 09/348,486, filed Jul. 7, 2001, now pending and hereby incorporated by reference in its entirety, which in turn claimed the benefit of U.S. Provisional Application Ser. No. 60/092,221 filed Jul. 8, 1998, also hereby incorporated by reference in its entirety. Additionally, U.S. Pat. No. 5,617,762 entitled “Miniature Positioning Device” issued Apr. 8, 1997, of common assignee herewith, is also incorporated by reference in its entirety.

BACKGROUND ART

[0002] Present day remote camera positioners are manually controlled systems wherein system operators manipulate joysticks in order to tilt and/or pan the positioner to desired locations. Some remote camera positioners also allow for the use of a joystick to teach the positioner to automatically move between prior programmed points for gathering information.

[0003] However, existing systems cannot accurately track a given remotely located target when either the target or the positioner (or both relative to each other) move over time. Further, these existing systems do not allow for the automatic tracking of a given target by the positioner without any operator involvement.

SUMMARY OF THE INVENTION AND ADVANTAGES

[0004] The system of the present invention allows for the onboard locating and tracking of remotely located objects from a search vehicle. This locating and tracking function is accomplished by first receiving two separate location signals onboard the search vehicle. The first location signal corresponds to the location of the remotely located object, which is transmitted by way of a transmitter located on the remote object. The first location signal is then received onboard the search vehicle by way of a transceiver. The second location signal corresponds to the location of the search vehicle itself. This second location signal is received by way of a receiver onboard the search vehicle. The first and second location signals are then processed together by a control processor, which determines a relative location between the remote object and the search vehicle. The control processor is further configured to move an image acquisition device, which includes a positioner containing a camera, in the direction of the remote object in accordance with the relative location mentioned above. The control processor continuously updates the determined relative position as updated values for the first and second location signals become available, to thereby track and maintain the established visual contact with the remote object. In one embodiment, the first and second location signals comprise Global Positioning System (GPS) location signals, wherein the above-mentioned transmitter, transceiver, and receivers are GPS-compliant.

[0005] The control processor may be configured to operate the image acquisition device automatically. However, in addition to operating in an “automatic” mode, the system may also be utilized in a number of other ways. For instance, a system operator may manually enter predetermined GPS coordinates, wherein the control processor is configured to move the positioner to focus on the corresponding location. The system may also be operated by manually manipulating a joystick to move the positioner in the direction the operator desires, or by manually manipulating the joystick until the desired target is found, and then depressing a button to “lock on” that target. The depression of the button causes the targets location information, such as its GPS coordinates, to be stored in a computer memory. The control processor is configured to first process this stored data with the succeeding coordinates that are received, and then to continuously track the target.

[0006] The invention has the added feature of a means of raising and lowering the positioner by use of an elevating mast. The positioner is mounted on a gimbaled platform. The combination of this gimbaled platform and the positioner are further mounted onto an elevating mast which allows for vertical movement in either an upward or downward direction along a vertical axis of the elevating mast, allowing for a wider range of viewing capabilities. The invention also provides a means for stabilizing the positioner, by taking into account and compensating for vehicle movement and mast sway of the elevating mast. This is accomplished by equipping the gimbaled platform with position control sensors that, in connection with the control processor, maintain the positioner in a horizontal relationship with the horizon.

[0007] One application of a system according to the invention involves search and rescue operations for making and maintaining visual contact with target vehicles and/or persons, perhaps in distress. The advantages of this invention over the current art are numerous. One such advantage is that the system, in one embodiment, receives and processes GPS signals, and then automatically moves the positioner in the appropriate direction in order to capture and maintain visual contact with a target object. This system is operational to acquire and maintain visual contact with the remote object (i.e., target) regardless of whether the search vehicle and remote object are moving. The invention also detects and compensates for both vehicle movement and the sway of the elevating mast in order to maintain a constant horizontal relationship with the horizon. The compensation function prevents losing visual contact with the remote object should the search vehicle or mast move in any fashion. Additionally, the system can automatically position a camera equipped with a zoom lens in order to make visual contact from distances that exceed human visual capability, or in weather conditions not conducive to maximum human efficiency. The GPS embodiment makes it possible for vehicles and persons equipped with transmitters integrated with GPS receivers to transmit their GPS coordinates, giving rescuers the ability to maintain a magnified camera fix on those in distress, to more safely and efficiently approach them.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings and diagrams wherein:

[0009]FIG. 1 is a block diagram of the overall GPS Image Acquisition and Tracking System;

[0010]FIG. 2 is a diagrammatic view of the Image Acquisition Device of the present invention;

[0011]FIG. 3 is a block diagram representing the relationship between the positioner, gimbaled platform and control processor;

[0012]FIG. 4 is a block diagram showing alternate modes of operation for the present invention; and

[0013]FIG. 5 is a flow diagram of the present invention.

DETAILED DESCRIPTION AND PREFERRED EMBODIMENT

[0014] Referring now to the Figures in which the same reference numerals are used to identify identical components in the various views, FIG. 1, shows a system 10 in accordance with the present invention. System 10 is configured to detect the position of and track a remote object such as a lost person 12. In an illustrated embodiment, system 10 makes use of an existing set of GPS-compliant satellites 14. System 10 includes a target unit 16, preferably co-located with the remote object 12, and a base unit 18, preferably co-located with a search vehicle 20 or the like. The remote object is herein referred to as being located at a first location whereas the search vehicle is referred to as being located at a second location.

[0015] Target unit 16 comprises a receiver 22 which receives coordinate location signals from a plurality of satellites 14, and calculates a first location using known methods. The first location may comprise geographic coordinate information, as known. Target unit 16 further includes a transmitter 24. For example, the first location determination may be accomplished by receiving digital radio signals emitted by satellites 14, and then measuring the time required for the radio signals to travel from satellites 14 to target unit 16. A first location signal corresponding to the determined first location may then be transmitted by way of a transmitter 24 located on target unit 16 to a corresponding transceiver 26 within base unit 18 located on search vehicle 20. The first location signal may be comprised of GPS coordinates of the remote object 12.

[0016] With continuing reference to FIG. 1, base unit 18 includes transceiver 26, a receiver 28, a control processor 30, and an image acquisition device 32. Receiver 28 is configured to receive the corresponding location coordinates for search vehicle 20 from the plurality of satellites 14. This is accomplished in the same way as the coordinates for remote object 12 are determined. Satellites 14 transmit digital radio signals to receiver 28, and then the time it takes for the radio signal to travel from satellites 14 to receiver 28 is measured. This results in the creation of a second location signal corresponding to the determined second location, which is sent to control processor 30. As with the first location signal, the second location signal may also be comprised of the GPS coordinates of search vehicle 20.

[0017] Control processor 30 is configured to receive first and second location signals from transceiver 26 and receiver 28, respectively, and calculate a relative location in response thereto. Control processor 30 may include a means for solving triangles, using logarithms, or other solution strategies known in the art. Control processor 30, in this regard, may be preprogrammed using software routines as known in the art. Control processor 30 is further configured to deliver drive signals to image acquisition device 32 in order to the device to automatically move in relation to the determined relative location, thereby establishing a visual contact with remote object 12.

[0018] Control processor 30 is further configured to continuously calculate the determined relative position as updated values for the first and second location signals become available. The continuous surveying of the location data thereby allows for the constant tracking and continued visual contact of remote object 12.

[0019] Referring to FIG. 2, image acquisition device 32 generally includes a mounting base 34, an elevating mast 36, a gimbaled platform 38, and a positioner 40. Mounting base 34 is affixed to search vehicle 20. Elevating mast 36 is affixed to mounting base 34, and has a vertical axis 42 associated therewith. Gimbaled platform 38 is mounted atop elevating mast 36, and positioner 40 is mounted upon gimbaled platform 38. Gimbaled platform 38 operates to maintain positioner 40, which includes, among other components, a spherical pitch wheel 44 and a camera 46, in a horizontal relationship with the horizon, and elevating mast 36 allows positioner 40 to be raised or lowered along axis 42 in order to provide extended viewing capabilities.

[0020] Referring to FIG. 3, positioner 40 is comprised of spherical pitch wheel 44, camera 46, position control sensors 48 and optical encoders 50. Pitch wheel 44, having both a pitch and yaw axis, houses camera 46 and is electrically connected to control processor 30. Pitch wheel 44 provides camera 46 with the capability of movement about both its pitch and yaw axis. The increased movement allows for the system to track or maintain the visual contact with remote object 12 for a predetermined time interval while either or both remote object 12 and search vehicle 20 move independently of each other. Positioner 40 may further be configured to provide for the coupling of other sensors such as light emitters and laser range finders/data scopes.

[0021] Optical encoders 50 allow the control processor 30 to control the position angles and speed of positioner 40 by delivering position and speed signals 52 of positioner 40 to control processor 30. Similarly, position control sensors 48 are also in electrical contact with control processor 30, and are used to detect and control maximum pitch movement of positioner 40 by sending position signals 54 to control processor 30. After processing these signals, control processor 30 sends drive signals to positioner 40 in order to control both the movement angles and speed of positioner 40.

[0022] Camera 46, housed within pitch wheel 44, gives the system the capability to visually capture and maintain visual contact with remote object 12. The image may be enhanced by zooming camera 46 in or out, and focusing the image by the use of a high-speed auto focus lens. To carry out these enhancements, camera 46 can be equipped with X12 optical zoom with electronic imaging stabilizing capabilities, electronic X24 digital zoom, high speed auto focus lens, and a RS232C serial control interface. Camera 46 may also be of the type that has the capability of “night vision” in order to be effective in dark conditions.

[0023] Additionally, positioner 40 may be equipped with a light or other illuminating device that may be used to illuminate remote object 12 should it be needed.

[0024] With continuing reference to FIG. 3, gimbaled platform 38 accounts for movement of search vehicle 20 and/or elevating mast 36 in order to maintain a horizontal relationship between positioner 40 and the horizon. This is accomplished by equipping gimbaled platform 38 with position control sensors 56. These sensors can be comprised of accelerometers and/or inclinometers, and they can be used to measure acceleration and movement angles placed on image acquisition device 32 by the movement of search vehicle 20 or elevating mast 36. Position control sensors 56 send position signals 58 corresponding to the movement of gimbaled platform 38 to control processor 30. Control Processor 30 processes these signals and delivers correcting drive signals to gimbaled platform 38, thereby allowing for the maintenance of the horizontal relationship between positioner 40 and the horizon.

[0025] Referring to FIG. 4, the system may also be operational should one decide to override the automatic location and tracking mode. The system may be equipped with joystick 60 which allows a system operator to manually control image acquisition device 32, particularly positioner 40 and elevating mast 36. Joystick 60 is electrically connected to control processor 30, which translates the operators commands, and moves image acquisition device 32 accordingly. Joystick 60 may also have the capability of “locking on” remote object 12 by providing a button that when depressed, freezes the image, and stores the location data of remote object 12. Control Process 30 processes the stored location data with succeeding coordinate signals in order to maintain visual contact with remote object 12.

[0026] With continued reference to FIG. 4, the system may also be equipped with keypad 62 which can be used to manually enter predetermined location coordinates of remote object 12. Keypad 62 is electrically connected to control processor 30, which, upon receiving said coordinates, moves image acquisition device 32 in conformity therewith.

[0027] Referring to FIG. 5, the inventive method can be best understood by way of an example. Target unit 16 is attached to a remotely located object 12 such as to a pilot whose plane has gone down, or to the life vest of a person who has fallen off a boat. Receiver 22 receives the GPS coordinate location signal corresponding to target unit 16, and therefore remote object 12, from a plurality of satellites 14. Transmitter 24 of target unit 16 then transmits this GPS coordinate location signal, known as the first location signal, into open space.

[0028] With continued reference to FIG. 5, search vehicle 20, equipped with transceiver 26 and receiver 28, receives both the transmitted first location signal from transmitter 24 by way of transceiver 26, and its own GPS coordinate location signal, known as the second location signal, from plurality of satellites 14. Transceiver 26 and receiver 28 then deliver the respective first and second location signals to control processor 30.

[0029] Control processor 30 continuously processes the first and second location signals in order to constantly update the relative location of remote object 12. Further, control processor 30 creates and delivers drive signals to image acquisition device 32 that correspond to the relative location of remote object 12. These signals cause positioner 40 and/or elevating mast 36 to move in the appropriate direction or directions in order to allow camera 46 to establish visual contact with remote object 12.

[0030] While positioner 40 and/or elevating mast 36 are moving, control processor 30 continuously processes the relative location with position and speed signals 52 from optical encoders 50, position signals 54 from position control sensors 48, and position signals 58 from gimbaled platform position control sensors 56, to produce and deliver drive signals to positioner 40 and gimbaled platform 38. These drive signals assist in the establishment and maintenance of visual contact by controlling the speed and movement angles of positioner 40. These drive signals are also delivered to gimbaled platform 38 to provide for the stabilization of positioner 40. The signals cause gimbaled platform 38 to be adjusted by taking into account the effect that wind and the movement of search vehicle 20 have on image acquisition device 32, thereby allowing for the maintenance of the horizontal relationship between positioner 40 and the horizon.

[0031] Once this visual contact is made with the remote object 12, search vehicle 20 may then retrieve the downed-pilot or overboard person while staying in constant visual contact with the object in order to rescue them in a safe manner.

[0032] The foregoing disclosure is intended merely to illustrate certain preferred embodiments of the invention. It is contemplated that those skilled in the art may find numerous ways to modify these embodiments without departing from the scope and spirit of the invention. As such, the scope of the invention is defined by the appended claims and not by the details of the specification. 

What I claim is:
 1. A method for operating an image acquisition device; comprising the steps of: providing a target at a first location thereof; determining and transmitting a first location signal corresponding to said first location from said target; receiving said first location signal at a search vehicle; determining a second location corresponding to the search vehicle with which said image acquisition device is associated and generating a second location signal corresponding to said second location; delivering said first and second location signals to a control processor; processing said delivered first and second location signals to produce a relative location of said target in relation to said search vehicle in response to said first and second location signals; moving said image acquisition device according to said relative location to thereby image said target from said search vehicle with a camera
 2. The method of claim 1, wherein the steps of determining said first and second locations are accomplished by receiving at each said location, digital radio signals transmitted via satellites, and measuring the time required for said digital radio signals to travel from said satellites to said first and second locations to produce an accurate postion for said target and said search vehicle;
 3. The method of claim 2 wherein the method is Global Positioning System compliant;
 4. The method of claim 1, performing said method as either or both of said target or said search vehicle moves.
 5. The method of claim 1 further comprising the step of stablizing said image acquisition device by use of position control sensors to take into account movement of said search vehicle.
 6. The method of claim 1, further comprising the step of controlling the speed and position of said image acquisition device by using optical encoders.
 7. The method of claim 1 further comprising the step of enhancing said image by zooming said image acquisition device in or out, and focusing said image by the use of a high-speed auto focus lens.
 8. The method of claim 1 further comprising the step of capturing and maintaining said image by the manual operation of a joystick which controls said positioner.
 9. The method of claim 1 further comprising the step of moving said image acquisition device by the manual entry of GPS coordinates by use of a keypad.
 10. The method of claim 1 further comprising the step of moving said image acquisition device by manipulating said joystick until said target is visually found, and then depressing a button on said joystick to capture and store the location of said remote object.
 11. A tracking system comprising: a transmitter configured to transmit a first location signal corresponding to a remote first location associated therewith; a base unit configured for use as a search vehicle including: a transceiver configured for use on a search vehicle for receiving said first location signal and delivers said first location signal to a control processor located on said search vehicle; a local position receiver configured to determine a second location of said search vehicle and generates a second location signal corresponding to said second location and delivers said second location signal to said control processor; said control processor that receives and processes said first and second location signals to produce a relative location of said remote first location in relation to said search vehicle; and a camera mounted upon a positioner arranged to move the camera based on said relative position so as to allow ongoing imaging of said remote first location
 12. The device of claim 11 wherein said first and second locations are determined by receiving at each said location digital radio signals transmitted via satellites, and measuring the time required for said digital radio signals to travel from said satellites to said remote first location and said search vehicle in order to produce an accurate position of said remote first location and said search vehicle.
 13. The device of claim 11, wherein said tracking system is Global Positioning System compliant.
 14. The device of claim 11, wherein said tracking system is operable as either or both said remote first location or said search vehicle moves.
 15. The device of claim 11, further comprising the capability of controlling the speed and position of said positioner by use of optical encoders which are in communication with said control processor.
 16. The device of claim 1 1, wherein said positioner further comprises a spherical shaped pitch wheel which houses said camera.
 17. The device of claim 11 wherein said visual image can be enhanced by equipping said camera with X12 optical zoom with electronic imaging stabilizing capabilities, electronic X24 digital zoom, highspeed auto focus lens and a RS232C serial control interface.
 18. The device of claim 11, further comprising a mounting base adapted to couple with a gimbaled platform to support and maintain said positioner in a horizontal relationship with the horizon, as well as to offset movements of said search vehicle.
 19. The device of claim 17 wherein said gimbaled platform is stabilized by use of position control sensors.
 20. The device of claim 11, further comprising an elevating mast to raise and lower said gimbaled platform and said positioner for extended viewing capabilities.
 21. The device of claim 11, wherein said positioner can be manually controlled by use of a joystick to locate and obtain said visual image of said remote object.
 22. The device of claim 11 wherein said positioner can be controlled by entering said remote frist location's GPS coordinates via a keypad.
 23. The device of claim 11 wherein said positioner can controlled by manipulating said joystick until said remote first location is found and then depressing a button to lock on said remote first location. 